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The purpose of this work is to characterize Portuguese painting ground layers from the 15th and 16th centuries (1450–1600), focusing particularly on the Coimbra, Lisbon, and Viseu workshops. Calcium sulfate, used regularly in these layers is common in the Iberian Peninsula as a natural resource. Its use is now confirmed, as already studied in Spanish paintings, and it was prepared generally by addition of animal glue. Besides the common esthetic language to the various painting workshops at the time, chalk/calcite (calcium carbonate), gypsum (di‐hydrated calcium sulfate), and anhydrite (anhydrous calcium sulfate) ground layers have specificities that allow characterizing different compounds. The cross‐sections from a set of six groups of Portuguese paintings were examined by optical microscopy and micro‐confocal Raman and Raman spectroscopic mapping imaged the location of the different compounds in the cross‐section. Results were integrated with those obtained by micro‐X‐ray diffraction and scanning electron microscopy with energy dispersive X‐ray spectroscopy on the same samples. In most cases, the ground layers are made of calcium sulfate in the form of the so‐called gesso grosso (mainly anhydrite with small amounts of gypsum). Differently, the Viseu paintings have calcium carbonate ground layers. These results put in evidence differences between the examined groups giving important information on the various workshop practices and also on the possible future conservative intervention on the paintings. Copyright © 2014 John Wiley & Sons, Ltd.

This article describes a study carried out on a mural painting in the Convent of Santo António dos Capuchos in the town of Estremoz (southern Portugal). Experimental work was undertaken to identify pigments and to elicit hypothesis about their local origin. Another aim was to ascertain the painting technique (binders, stratigraphy) and to try to investigate the causes that led to the deterioration of the blue and green pigments. Elemental and mineralogical analyses of the pigments were performed by x‐ray diffraction (µ‐XRD), portable energy dispersive x‐ray fluorescence (EDXRF) and scanning electron microscopy (SEM), complemented by microchemical tests and Fourier transform infrared spectroscopy (FTIR). These techniques have shown that a variety of pigments were used, namely earth pigments (red and yellow ochres, green earth and probably black earth and umber), copper pigments (azurite, malachite), probably from the Estremoz region, and smalt, used pure or in mixtures. The results also revealed the presence of salt veils, biological colonization and possibly secco applications with lime (lime painting), which may have contributed to the actual state of conservation of fresco. Copyright © 2008 John Wiley & Sons, Ltd.

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The tomb of D. Afonso of Portugal (1390‐1400), king D. João I first born raises questions about the production of its different elements, which according to their typology were not all made simultaneously. The singularity of both the composition of the metal and the type of techniques ‐ fire gilding and amalgam silvering ‐ used in the decoration of some elements causes difficulties in the attribution of the tomb to a Flanders or to a Portuguese workshop. The aim of this work is to attribute to the tomb a possible production origin based on the study of the copper provenance. Special attention was given to decorative techniques because these could bring further information about the production of the elements. For these purposes PIXE and SEM‐EDS analysis were used. PIXE analysis revealed the importance given to the choice of an almost pure copper for the tomb pieces, since it has a direct consequence in the manufacture and decorative techniques. It also allowed concluding that the composition of the pieces correlates very well with the coins minted during D. Afonso V period, further studies being necessary to compare the results with objects from Flanders. Analysis by SEM/EDS characterized the gilded coating as being made of a layer of Au + Hg applied by fire amalgam. In the silvered coating, the existence of two separate layers characterises the silvering technique as having been executed by the application of an Ag + Hg amalgam, on top of a first layer of Au + Hg, also applied by amalgam. Copyright © 2008 John Wiley & Sons, Ltd.

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This work regards the methodology used on the preparation of ground layer techniques in Portuguese and Flemish workshops of the 15th and early 16th centuries.

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